Phenom II X2 B55 vs Core 2 Quad Q8400
Aggregate performance score
Core 2 Quad Q8400 outperforms Phenom II X2 B55 by an impressive 76% based on our aggregate benchmark results.
Primary details
Comparing Core 2 Quad Q8400 and Phenom II X2 B55 processor market type (desktop or notebook), architecture, sales start time and price.
| Place in the ranking | 2268 | 2657 |
| Place by popularity | not in top-100 | not in top-100 |
| Cost-effectiveness evaluation | no data | 2.02 |
| Market segment | Desktop processor | Desktop processor |
| Power efficiency | 1.30 | 0.88 |
| Architecture codename | Yorkfield (2007−2009) | Callisto (2009−2010) |
| Release date | 19 April 2009 (15 years ago) | 1 October 2009 (15 years ago) |
| Launch price (MSRP) | no data | $48 |
Cost-effectiveness evaluation
Performance per price, higher is better.
Detailed specifications
Core 2 Quad Q8400 and Phenom II X2 B55 basic parameters such as number of cores, number of threads, base frequency and turbo boost clock, lithography, cache size and multiplier lock state. These parameters indirectly say of CPU speed, though for more precise assessment you have to consider their test results.
| Physical cores | 4 (Quad-Core) | 2 (Dual-core) |
| Threads | 4 | 2 |
| Base clock speed | 2.66 GHz | 3 GHz |
| Boost clock speed | 0.67 GHz | 3 GHz |
| Bus rate | 1333 MHz | no data |
| L1 cache | 64 KB (per core) | 128 KB (per core) |
| L2 cache | 4 MB (shared) | 512 KB (per core) |
| L3 cache | 0 KB | 6 MB (shared) |
| Chip lithography | 45 nm | 45 nm |
| Die size | 2x 82 mm2 | 258 mm2 |
| Maximum case temperature (TCase) | 71 °C | no data |
| Number of transistors | 456 million | 758 million |
| 64 bit support | + | + |
| Windows 11 compatibility | - | - |
| VID voltage range | 0.85V-1.3625V | no data |
Compatibility
Information on Core 2 Quad Q8400 and Phenom II X2 B55 compatibility with other computer components: motherboard (look for socket type), power supply unit (look for power consumption) etc. Useful when planning a future computer configuration or upgrading an existing one. Note that power consumption of some processors can well exceed their nominal TDP, even without overclocking. Some can even double their declared thermals given that the motherboard allows to tune the CPU power parameters.
| Number of CPUs in a configuration | 1 | 1 |
| Socket | FCLGA775,LGA775 | AM3 |
| Power consumption (TDP) | 95 Watt | 80 Watt |
Technologies and extensions
Technological solutions and additional instructions supported by Core 2 Quad Q8400 and Phenom II X2 B55. You'll probably need this information if you require some particular technology.
| Enhanced SpeedStep (EIST) | + | no data |
| Turbo Boost Technology | - | no data |
| Hyper-Threading Technology | - | no data |
| Idle States | + | no data |
| Thermal Monitoring | + | - |
| Demand Based Switching | - | no data |
| FSB parity | - | no data |
Security technologies
Core 2 Quad Q8400 and Phenom II X2 B55 technologies aimed at improving security, for example, by protecting against hacks.
| TXT | - | no data |
| EDB | + | no data |
Virtualization technologies
Virtual machine speed-up technologies supported by Core 2 Quad Q8400 and Phenom II X2 B55 are enumerated here.
| AMD-V | - | + |
| VT-x | + | no data |
Memory specs
Types, maximum amount and channel quantity of RAM supported by Core 2 Quad Q8400 and Phenom II X2 B55. Depending on the motherboard, higher memory frequencies may be supported.
| Supported memory types | DDR1, DDR2, DDR3 | DDR3 |
Graphics specifications
General parameters of integrated GPUs, if any.
| Integrated graphics card | On certain motherboards (Chipset feature) | On certain motherboards (Chipset feature) |
Peripherals
Specifications and connection of peripherals supported by Core 2 Quad Q8400 and Phenom II X2 B55.
| PCIe version | 2.0 | 2.0 |
Synthetic benchmark performance
Various benchmark results of the processors in comparison. Overall score is measured in points in 0-100 range, higher is better.
Combined synthetic benchmark score
This is our combined benchmark performance rating. We are regularly improving our combining algorithms, but if you find some perceived inconsistencies, feel free to speak up in comments section, we usually fix problems quickly.
Passmark
Passmark CPU Mark is a widespread benchmark, consisting of 8 different types of workload, including integer and floating point math, extended instructions, compression, encryption and physics calculation. There is also one separate single-threaded scenario measuring single-core performance.
GeekBench 5 Single-Core
GeekBench 5 Single-Core is a cross-platform application developed in the form of CPU tests that independently recreate certain real-world tasks with which to accurately measure performance. This version uses only a single CPU core.
GeekBench 5 Multi-Core
GeekBench 5 Multi-Core is a cross-platform application developed in the form of CPU tests that independently recreate certain real-world tasks with which to accurately measure performance. This version uses all available CPU cores.
Pros & cons summary
| Performance score | 1.30 | 0.74 |
| Recency | 19 April 2009 | 1 October 2009 |
| Physical cores | 4 | 2 |
| Threads | 4 | 2 |
| Power consumption (TDP) | 95 Watt | 80 Watt |
Core 2 Quad Q8400 has a 75.7% higher aggregate performance score, and 100% more physical cores and 100% more threads.
Phenom II X2 B55, on the other hand, has an age advantage of 5 months, and 18.8% lower power consumption.
The Core 2 Quad Q8400 is our recommended choice as it beats the Phenom II X2 B55 in performance tests.
Should you still have questions on choice between Core 2 Quad Q8400 and Phenom II X2 B55, ask them in Comments section, and we shall answer.
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